Process for increasing the sun protection factor of cellulosic fiber materials

ABSTRACT

Process for increasing the sun protection factor of cellulosic fibre materials by treating the cellulosic fibre materials with at least one direct dye and at least one UV absorber.

The present invention relates to a process for increasing the sun protection factor of cellulosic fibre materials, which comprises treating the cellulosic fibre materials with direct dyes in the presence of at least one UV absorber.

The skin-damaging effect of UV radiation is known. Protection from strong sunlight is usually sought by applying a sun cream, a composition that contains a UV absorber, directly to the skin. In particularly sunny climes, for example in Australia or America, however, the rate of skin damage due to UV radiation has lately been increasing. Accordingly, more attention is paid in these countries to protecting the skin from the sun's rays.

It has therefore been proposed that not only to protect the skin directly, but also to reduce the UV transmissivity of the clothing and also of other sun protection articles fabricated from cellulosic fibre materials, such as awnings or parasols. Most undyed fibre materials are at least partially transparent to UV radiation, so that the mere wearing of clothes does not offer adequate protection to the skin from damage due to UV radiation.

However, the results achieved hitherto in respect of the protection from UV radiation in the area of cellulosic fibre materials, in particular textile materials, have not been satisfactory and there therefore continues to be a need for improving the sun protection factor of these materials.

It has now been found, surprisingly, that even better sun protection can be achieved if cellulosic fibre materials are treated with a combination of direct dyes and UV absorbers.

The present invention accordingly provides a process for increasing the sun protection factor of cellulosic fibre materials, which comprises treating the cellulosic fibre materials with at least one direct dye and at least one UV absorber.

In the process of the present invention, the amounts in which the direct dyes are used in the dyebaths may vary with the desired depth of shade; in general, advantageous amounts range from 0.001 to 10% by weight, in particular from 0.001 to 5% by weight, based on the weight of the fibre material.

The amounts of UV absorbers used in the process of the present invention can vary between 0.001 and 5% by weight, based on the weight of the fibre material.

In a preferred embodiment of the process of the present invention, the amount of UV absorber used depends on the total amount of dye used. For instance, the amount of UV absorber used is from 0.2 to 5% by weight, in particular from 0.2 to 2% by weight, based on the weight of the fibre material, in the case of pale shades, from 0.05 to 0.2% by weight in the case of medium shades and from 0.001 to 0.05% by weight in the case of deep shades. Pale shades are to be understood as meaning those where the amount of dye used is from 0.001 to 0.2% by weight, based on the weight of the fibre material. Medium shades are those where the amount of dye used is from 0.2 to 2.0% by weight and deep shades are those where the amount of dye used is from 2 to 10% by weight, in particular from 2 to 5% by weight.

In a particularly preferred embodiment of the process of the present invention, the amount of direct dye used is from 0.2 to 2.0% by weight, based on the weight of the fibre material, and the amount of UV absorber used is from 0.05 to 0.2% by weight, based on the weight of the fibre material.

In a very particularly preferred embodiment of the process of the present invention, the amount of direct dye used is from 0.001 to 0.2% by weight, based on the weight of the fibre material, and the amount of UV absorber used is from 0.2 to 2% by weight, based on the weight of the fibre material.

The process of the present invention makes it possible to achieve an adequate sun protection factor in fibre material dyed or printed in any desired shade, an adequate sun protection factor being a sun protection factor with a value of at least 25.

Advantageously, the amount of direct dye used is selected so as to result in an increase of the sun protection factor of cellulosic fibre materials by at least a factor of 5.

Direct dyes are to be understood for example as meaning those dyes which are described as direct dyes in the Colour Index, 3rd edition (3rd revision 1987 including additions and amendments up to No. 85).

The direct dyes used are in particular phthalocyanine dyes, dioxazine dyes and dyes of the formula

    A.sub.1 --B.sub.1 --A.sub.2                                ( 1)

where B₁ is a bridge member and A₁ and A₂ are independently of each other the radical of a monoazo, polyazo, metal complex azo, stilbene or anthraquinone dye, or where B₁ and A₁ are each as defined above and A₂ is a phenyl or naphthyl radical substituted by a heterocyclic radical or by a benzoylamino or phenylamino radical, or where B₁ is a direct bond and A₁ and A₂ are each the radical of a metal complex azo dye.

Suitable bridge members B₁ in the formula (1) include for example: ##STR1## where R₁ and R₂ are independently of each other unsubstituted or halogen-, hydroxyl-, cyano-, C₁ -C₄ alkoxy-, C₁ -C₄ alkoxycarbonyl-, carboxyl-, sulfamoyl-, sulfo- or sulfato-substituted C₁ -C₈ alkyl; or in particular hydrogen; X₁ and X₂ are each bridge members; and Y and Y₁ are independently of each other hydroxyl, C₁ -C₄ alkoxy, chlorine, bromine, C₁ -C₄ alkylthio, amino, unsubstituted or hydroxyl-, sulfo-, carboxyl- or C₁ -C₄ alkoxy-substituted (in the alkyl moiety) N-mono- or N,N-di-C₁ -C₄ alylamino, cyclohexylamino, unsubstituted or C₁ -C₄ alkyl, C₁ -C₄ alkoxy-, carboxyl-, sulfo- and/or halogen-substituted (in the phenyl moiety) phenylamino or N-C₁ -C₄ alkyl-N-phenylamino, morpholino or 3-carboxy- or 3-carbamoyl-pyridin-1-yl.

The bridge member X₁ in the formula (2c) is preferably unsubstituted or hydroxyl-, sulfo-, sulfato-, C₁ -C₄ alkoxy-, carboxyl- or halogen-substituted C2-C₆ alkylene; unsubstituted or hydroxyl-, sulfo-, sulfato-, C₁ -C₄ alkoxy-, carboxyl- or halogen-substituted C₅ -C₉ cycloalkylene; unsubstituted or C₁ -C₄ alkyl-, C₁ -C₄ -alkoxy-, sulfo-, halogen- or carboxyl-substituted phenylene; unsubstituted or C₁ -C₄ alkyl-, C₁ -C₄ -alkoxy-, sulfo-, halogen- or carboxyl-substituted biphenylene; or unsubstituted or C₁ -C₄ alkyl-, C₁ -C₄ -alkoxy-, sulfo-, halogen- or carboxyl-substituted naphthalene radical. X₁ is in particular unsubstituted or sulfo-substituted phenylene.

A bridge member X₂ in the formula (2e) can be for example a radical of the formula ##STR2## and in particular ##STR3## where R₁ and R₂ are each subject to the previously indicated definitions and preferences.

Preference is given to the use of direct dyes of the formula

    A.sub.1 --NH--L.sub.1                                      ( 1a)

where

A₁ is as defined under the formula (1) and L₁ is a radical of the formulae ##STR4## where X₃ and X₄ are independently of each other a direct bond, NH, NR₅, O or S; R₃ and R₄ are independently of each other hydrogen; aromatic, aliphatic or cycloaliphatic radicals, which are unsubstituted or substituted by halogen, OR₅, COOR₅, SO₃ H or aralkyl, which may be substituted by halogen, OR₅, COOR₅ or SO₃ H; and R₅ is hydrogen or C₁ -C₆ alkyl.

The radicals R₃ and R₄ in the formula (1a) are preferably C₁ -C₆ alkyls or C₁ -C₆ alkylenes, for example methyl, ethyl or isopropyl, which may each be substituted, for example by carboxyl or phenyl; or phenols, which may likewise be substituted, for example by carboxyl; unsubstituted or substituted benzyl radicals; or radicals of the formulae ##STR5## where R₅ is as defined under the formula (1a).

Preference is likewise given to using dyes of the formula (1) where B₁ and A₁ are each as defined and A₂ is a benzothiazolyl-, benzisothiazolyl- or naphthotriazolyl-substituted phenyl radical, where the phenyl radical and the benzothiazolyl, benzisothiazolyl and naphthotriazolyl substituents on the phenyl radical can independently of one another be substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl, hydroxyl, sulfo, sulfamoyl, ureido, amino optionally further substituted by C₁ -C₄ alkyl, C₁ -C₄ hydroxyalkyl, or C₂ -C₆ alkanoyl or C₂ -C₆ alkanoylamino optionally further substituted (in the alkyl moiety) by hydroxyl.

The radicals A₁ and A₂ in the formula (1) can be substituted, for example by C₁ -C₄ alkyl, such as methyl, ethyl, propyl, isopropyl or butyl; C₁ -C₄ alkoxy, such as methoxy, ethoxy, propoxy, isopropoxy or butoxy; C₁ -C₈ acylamino, in particular unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₁ -C₈ alkanoylamino, such as acetylamino or propionylamino; unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₁ -C₈ alkoxycarbonylamino, such as methoxycarbonylamino or ethoxycarbonylamino; benzoylamino; phenylamino, N,N-di-β-hydroxyethylamino; N,N-di-β-sulfatoethylamino; sulfobenzylamino; N,N-disulfobenzylamino; unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoyl; phenylazo; naphthotriazolyl; benzothiazolyl; benzisothiazolyl; C₁ -C₄ alkoxycarbonyl, such as methoxycarbonyl or ethoxycarbonyl; C₁ -C₄ alkylsulfonyl, such as methylsulfonyl or ethylsulfonyl; trifluoromethyl; nitro; cyano; halogen, such as fluorine, chlorine or bromine; carbamoyl, N-C₁ -C₄ alkylcarbamoyl, such as N-methylcarbamoyl or N-ethylcarbamoyl; sulfamoyl; N-C₁ -C₄ alkylsulfamoyl, such as N-methylsulfamoyl, N-ethylsulfamoyl, N-propylsulfamoyl, N-isopropylsulfamoyl or N-butylsulfamoyl; N-phenylsulfamoyl; ureido; hydroxyl; carboxyl; sulfomethyl; sulfo; or unsubstituted or C₁ -C₄ alkyl- or C₁ -C₄ hydroxyalkyl-substituted amino; where the abovementioned heterocyclic radicals and also the groups that contain a phenyl radical can be further substituted by one or more of the groups mentioned above as substituents for the radicals A₁ and A₂.

Any C₁ -C₄ alkyl, C₁ -C₆ alkyl or C₁ -C₈ alkyl in the formulae is for example, in accordance with the stated chain length, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl or octyl.

Any C₁ -C₄ alkoxy in the formulae is for example methoxy, ethoxy, propoxy, isopropoxy, isobutoxy or tert-butoxy.

Any C₁ -C₄ hydroxyalkyl in the formulae is for example 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl, 2,3-dihydroxypropyl or 3,4-dihydroxybutyl.

Any N-mono-C₁ -C₄ alkylamino in the formulae is for example N-methylamino, N-ethylamino, N-propylaminio or N-butylamino.

Any N,N-di-C₁ -C₄ alkylamino in the formulae is for example N,N-dimethylamino, N,N-diethylamino, N,N-dipropylamino, N-methyl-N-ethylamino, N-ethyl-N-propylamino or N-ethyl-N-butylamino.

Any N-C₁ -C₄ alkyl-N-phenylamino in the formulae is for example N-methyl-N-phenylamino, N-ethyl-N-phenylamino, N-propyl-N-phenylamino or N-butyl-N-phenylamino.

Any C₂ -C₆ alkanoylamino or C₁ -C₈ alkanoylamino in the formulae is for example acetylamino, propionylamino or n-butyrylamino.

Any C₁ -C₄ alkoxycarbonyl in the formulae is for example methoxycarbonyl, ethoxycarbonyl or propoxycarbonyl.

Any C₂ -C₆ alkylene in the formulae is for example methylene, ethylene, propylene, tetramethylene, pentamethylene or hexamethylene.

Any C₅ -C₉ cycloalkylene in the formulae is for example cyclopentylene, cyclohexylene or cycloheptylene.

Any C₂ -C₆ alkanoyl in the formulae is for example acetyl, propionyl or n-butyryl.

Any C₁ -C₄ alkylthio in the formulae is for example methylthio, ethylthio, propylthio or butylthio.

Azo dye radicals A₁ and A₂ are preferably radicals of the formula ##STR6## where D₁ is the radical of a diazo component of the benzene or naphthalene series, M₁ is the radical of a middle component of the benzene or naphthalene series, K₁ is the radical of a coupling component of the benzene or naphthalene series, and D₁, M₁ and K₁ may be substituted by the substituents indicated above for A₁ and A₂, in particular by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl, hydroxyl, sulfo, sulfamoyl, ureido, unsubstituted or C₁ -C₄ alkyl- or C₁ -C₄ hydroxyalkyl-substituted amino, unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoyl, unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoylamino, unsubstituted or carboxyl-, halogen-, sulfo-, C₁ -C₄ alkyl- or C₁ -C₄ alkoxy-substituted (in the phenyl ring) phenylamino, or unsubstituted or carboxyl-, halogen-, sulfo-, C₁ -C₄ alkyl- or C₁ -C₄ alkoxy-substituted (in the phenyl ring) benzoylamino;

Metal complex azo dye radicals A₁ and A₂ are preferably radicals of the formula ##STR7## where the oxygen or the carboxyl group is bonded to the radical Q₁, Q₂ or Q₃ in an ortho position relative to the azo group and Q₁, Q₂ or Q₃ are each independently of the others a radical of the benzene or naphthalene series, and Q₁, Q₂ and Q₃ may be substituted by the substituents indicated above for A₁ and A₂, in particular by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl, hydroxyl, sulfo, sulfamoyl, ureido, unsubstituted or C₁ -C₄ alkyl- or C₁ -C₄ hydroxyalkyl-substituted amino, unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoyl, unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoylamino, unsubstituted or carboxyl-, halogen-, hydroxyl-, sulfo-, C₁ -C₄ alkyl-, C₁ -C₄ alkoxy- or C₁ -C₄ carboxyalkoxy-substituted (in the phenyl ring) phenylamino, or unsubstituted or carboxyl-, halogen-, hydroxyl-, sulfo-, C₁ -C₄ alkyl-, C₁ -C₄ alkoxy- or C₁ -C₄ carboxyalkoxy-substituted (in the phenyl ring) benzoylamino, or unsubstituted or carboxyl-, halogen-, hydroxyl-, sulfo-, C₁ -C₄ alkyl-, C₁ -C₄ alkoxy- or C₁ -C₄ carboxyalkoxy-substituted (in the phenyl ring) phenylazo;

Stilbene dye radicals A₁ and A₂ are preferably radicals of the formula ##STR8## where the benzene rings I and II may independently of each other be substituted by the substituents indicated above for A₁ and A₂, in particular by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl, hydroxyl, sulfo, sulfamoyl, ureido, unsubstituted or C₁ -C₄ alkyl- or C₁ -C₄ hydroxyalkyl-substituted amino, unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoyl, unsubstituted or hydroxyl-substituted (in the alkyl moiety) C₂ -C₆ alkanoylamino, or unsubstituted or C₁ -C₄ alkyl-, C₁ -C₄ alkoxy-, halogen- or sulfo-substituted naphthotriazole;

Anthraquinone dye radicals A₁ and A₂ are preferably radicals of the formula ##STR9## where G₁ is C₂ -C₆ alkylene, cyclohexylene, phenylenemethylene or preferably phenylene, the anthraquinone nucleus may be substituted by a further sulfo group, and phenylene G₁ may be substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl or in particular sulfo;

A heterocyclyl-substituted phenyl or naphthyl radical A₂ is preferably a benzothiazolyl-, benzisothiazolyl- or naphthotriazolyl-substituted phenyl radical, where the phenyl radical and the benzothiazolyl, benzisothiazolyl and naphthotriazolyl substituents on the phenyl radical can independently of one another be substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl, hydroxyl, sulfo, sulfamoyl, ureido, amino optionally further substituted by C₁ -C₄ alkyl or C₁ -C₄ hydroxyalkyl, or C₂ -C₆ alkanoyl or C₂ -C₆ alkanoylamino optionally further substituted (in the alkyl moiety) by hydroxyl.

Dyes of the formula (1) where B₁ is a bridge member may contain identical or different radicals of the formulae (4a), (4b), (5a), (5b), (6) and (7) for A₁ and A₂. Similarly, dyes of the formula (1) where B₁ is a direct bond may contain identical or different radicals of the formulae (5a) and (5b) for A₁ and A₂.

The phthalocyanine direct dyes suitable for the use according to the present invention preferably contain the radical of the formula ##STR10## where Pc is the radical of a copper or nickel phthalocyanine, W is --OH and/or --NR₇ R₈, R₇ and R₈ are independently of each other hydrogen or unsubstituted or hydroxyl- or sulfo-substituted C₁ -C₄ alkyl, R₆ is hydrogen or C₁ -C₄ alkyl, E is unsubstituted or C₁ -C₄ alkyl-, halogen-, carboxyl- or sulfo- substituted phenylene, or a C₂ -C₆ alkylene, preferably a sulphophenylene or ethylene, and k is 1, 2 or 3.

The dioxazine direct dyes suitable for the use according to the present invention preferably contain the radicals of the formulae ##STR11## where E₁ is unsubstituted or C₁ -C₄ alkyl-, halogen-, carboxyl- or sulfo-substituted phenylene or a C₂ -C₆ alkylene; and the outer benzene rings in the formulae (9a) and (9b) may be further substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, acetylamino, nitro, halogen, carboxyl or sulfo.

Particular preference is given to using direct dyes of the formula (1) where B₁ is a bridge member of the formulae (2a) to (2i) and A₁ and A₂ are independently of each other a radical of the formulae (4a), (4b), (5a), (5b), (6) and (7) or direct dyes of the formula (1) where B₁ and A₁ are each as defined and A₂ is a benzothiazolyl-, benzisothiazolyl- or naphthotriazolyl-substituted phenyl radical, where the phenyl radical and the benzothiazolyl, benzisothiazolyl and naphthotriazolyl substituents on the phenyl radical can independently of one another be substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, carboxyl, hydroxyl, sulfo, sulfamoyl, ureido, amino optionally further substituted by C₁ -C₄ alkyl, C₁ -C₄ hydroxyalkoxy, or C₂ -C₆ alkanoyl or C₂ -C₆ alkanoylamino optionally further substituted (in the alkyl moiety) by hydroxyl. or direct dyes of the formula (1) where B₁ is a direct bond and A₁ and A₂ are independently of each other a radical of the formulae (5a) and (5b).

Particular preference is likewise given to using direct dyes of the formula (1a) where L₁ is a radical of the formulae ##STR12## where X₆ is halogen and R₅ is as defined under the formula (1a).

The direct dyes preferably contain at least one water-solubilizing group, such as a sulfo or sulfato group, and are in this case present either in the form of their free acid or preferably as salts thereof, for example the alkali metal, alkaline earth metal or ammonium salts, or as salts of an organic amine. Examples are the sodium, potassium, lithium or ammonium salts or the salt of triethanolamine.

The direct dyes are known or can be prepared analogously to known dyes.

UV absorbers suitable for the process of the present invention are for example water-solubilized UV absorbers as known for example from U.S. Pat. No. 4,141,903; U.S. Pat. No. 4,230,867; U.S. Pat. No. 4,698,064 and U.S. Pat. No. 4,770,667.

It is possible to use for example the following compounds:

a) 2-hydroxybenzophenones of the formula ##STR13## where R₉ is hydrogen, hydroxyl, C₁ -C₁₄ alkoxy or phenoxy, R₁₀ is hydrogen, halogen, C₁ -C₄ alkyl or sulfo, R₁₁ is hydrogen, hydroxyl or C₁ -C₄ alkoxy, and R₁₂ is hydrogen, hydroxyl or carboxyl;

b) 2-(2'-hydroxyphenyl)-benzotriazoles of the formula ##STR14## R₁₃ is hydrogen, chlorine, sulfo, C₁ -C₁₂ alkyl, C₅ -C₆ cycloalkyl, (C₁ -C₈ alkyl)phenyl, C₇ -C₉ phenylalkyl or sulfonated C₇ -C₉ phenylalkyl, R₁₄ is hydrogen, chlorine, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxyl or sulfo, R₁₅ is C₁ -C₁₂ alkyl, chlorine, sulfo, C₁ -C₄ alkoxy, phenyl, (C₁ -C₈ alkyl)phenyl, C₅ -C₆ cycloalkyl, C₂ -C₉ alkoxycarbonyl, carboxyethyl, C₇ -C₉ phenylalkyl or sulfonated C₇ -C₉ phenylalkyl, R₁₆ is hydrogen, chlorine, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₂ -C₉ alkoxycarbonyl, carboxyl or sulfo, and R₁₇ is hydrogen or chlorine;

c) 2-(2'-hydroxyphenyl)-s-triazines of the formula ##STR15## where R₁₈ is hydrogen, halogen, C₁ -C₄ alkyl or sulfo, R₁₉ is hydrogen, C₁ -C₄ alkyl, C₁ -C₄ alkoxy or hydroxyl, R₂₀ is hydrogen or sulfo, and R₂₁ and R₂₂ are independently of each other C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₅ -C₆ cycloalkyl, phenyl or C₁ -C₄ alkyl- and/or hydroxyl-substituted phenyl;

d) s-triazine compounds of the formula ##STR16## where at least one of the substituents R₂₃, R₂₄ and R₂₅ is a radical of the formula ##STR17## where A is C₃ -C₄ alkylene or 2-hydroxytrimethylene and M' is sodium, potassium, calcium, magnesium, ammonium or tetra-C₁ -C₄ alkylammonium and b is 1 or 2, and the remaining substituent is or the remaining substituents are independently of each other C₁ -C₁₂ alkyl, phenyl, C₁ -C₁₂ alkyl or phenyl attached to the triazinyl radical by oxygen, sulfur, imino or C₁ -C₁₁ alkylimino, or a radical of the formula (14), for example the potassium salt of the compound of the formula (13) where R₂₃ is phenyl and R₂₄ and R₂₅ are each the radical of the formula (14) or the sodium salt of the compound of the formula (13) where R₂₃ is p-chlorophenyl and R₂₄ and R₂₅ are each the radical of the formula (14).

C₁ -C₁₄ Alkoxy R₉ is for example methoxy, ethoxy, propoxy, n-butoxy, octyloxy, dodecyloxy or tetradecyloxy;

C₁ -C₄ Alkyl R₁₀, R₁₄, R₁₆, R₁₈, R₁₉, R₂₁ or R₂₂ is methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl;

Sulfo R₁₀, R₁₃, R₁₄, R₁₅, R₁₆, R₁₈ or R₂₀ is present in free form or in salt form, for example as alkali metal, alkaline earth metal, ammonium or amine salts.

C₁ -C₄ Alkoxy R₁₁, R₁₄, R₁₅, R₁₆, R₁₉, R₂₁ or R₂₂ is for example methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy;

Carboxyl R₁₂ or R₁₆ may be present in free form or in salt form, for example as alkali metal, alkaline earth metal, ammonium or amine salt.

C₅ -C₆ Cycloalkyl R₁₃, R₁₅, R₂₁ or R₂₂ is for example cyclopentyl or cyclohexyl;

(C₁ -C₈ alkyl)phenyl, for example methylphenyl, tert-butylphenyl, tert-amylphenyl or tert-octylphenyl;

C₁ -C₁₂ alkyl R₁₃, R₁₅, R₂₃, R₂₄ or R₂₅ is for example methyl, ethyl, amyl, tert-octyl, n-dodecyl, sec-butyl or tert-butyl;

C₇ -C₉ phenylalkyl R₁₃ or R₁₅ is for example benzyl, α-methylbenzyl or preferably α,α-dimethylbenzyl;

C₂ -C₉ alkoxycarbonyl R₁₅ or R₁₆ is for example ethoxycarbonyl, n-octoxycarbonyl or preferably methoxycarbonyl;

C₁ -C₁₁ alkylamino R₂₃, R₂₄ or R₂₅ is for example methyl-, ethyl-, butyl-7, hexyl-, octyl-, decyl- or undecyl-imino.

(e) Water-soluble, asymmetrical oxalic diarylamides of the formula ##STR18## where R₂₆ is unsubstituted or hydroxyl- or alkoxy-substituted C₁ -C₅ alkyl or unsubstituted or C₁ -C₅ alkyl-substituted benzyl; R₂₇ is hydrogen; halogen; C₁ -C₁₂ alkyl or phenyl-C₁ -C₅ alkyl; R₂₈ is hydrogen; halogen; C₁ -C₁₂ alkyl, phenyl-C₁ -C₅ alkyl or C₁ -C₅ alkoxy; B is a direct bond or a bivalent radical of the formula --O--L--, where L is unsubstituted or hydroxyl-substituted C₁ -C₆ alkylene; M" is hydrogen or an alkali metal and r is 2; 1 or 0.

A C₁ -C₅ alkyl R₂₆ is for example methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl or isoamyl;

a halogen R₂₇ or R₂₈ is for example fluorine, bromine or chlorine. Chlorine is preferred. C₁ -C₁₂ Alkyl radicals R₂₇ and R₂₈ can be branched or unbranched radicals, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl, isoamyl, pentyl, neopentyl, tert-pentyl, hexyl, isohexyl, heptyl, octyl, isooctyl, nonyl, decyl, undecyl or dodecyl.

A phenyl-C₁ -C₅ alkyl R₂₇ or R₂₈ is for example phenethyl, phenylpropyl, phenylbutyl or preferably benzyl.

A C₁ -C₅ alkoxy R₂₈ is for example methoxy, ethoxy, isopropoxy, isobutoxy, tert-butoxy or tert-amyloxy.

A C₁ -C₆ alkylene L is a bivalent, saturated hydrocarbon radical, for example methylene, ethylene, propylene, trimethylene, tetramethylene, ethylethylene, pentamethylene or hexamethylene.

An alkali metal M" is for example lithium, sodium or potassium. Sodium is preferred.

The UV absorber of the formula (15) is preferably a compound where L is trimethylene or ##STR19##

A further preferred oxalic diarylamide conforms to the previously indicated formula (15) where R₂₈ is C₁ -C₁₂ alkyl or C₁ -C₅ alkoxy.

A similarly preferred UV absorber (e) is a compound of the previously indicated formula (15) where R₂₆ is C₁ -C₃ alkyl; R₂₇ is hydrogen; C₁ -C₃ alkyl or C₁ -C₃ alkoxy; R₂₈ is hydrogen; C₁ -C₃ alkyl or C₁ -C₃ alkoxy; B is a direct bond or the radical -- O--(CH₂)₃ !_(s) ; r is 0; 1 or 2;and s is 0 or 1.

A very particularly preferred UV absorber (e) is a compound of the formula (15) where r is 0 or 1, R₂₆ is methyl; ethyl; methoxy or ethoxy; R₂₇ is hydrogen or ethyl; R₂₈ is hydrogen or C₁ -C₃ alkoxy; B is the radical -- O--(CH₂)₃ !_(s) and s is 0 or 1.

Emphasis for use as UV absorber (e) is given in particular to the compound of the formula ##STR20##

The oxalic diarylamides according to (e) are known for example from EP-A 0 507 732 or can be obtained by the methods indicated therein.

Preferably the UV absorbers used in the process of the present invention are reactive UV absorbers.

Reactive UV absorbers are to be understood as meaning those UV absorbers which contain one or more reactive groups. Reactive groups are to be understood as meaning fibre-reactive radicals which are capable of reacting with the hydroxyl groups of cellulose, the amino, carboxyl, hydroxyl and thiol groups of wool and silk or with the amino and possibly carboxyl groups of synthetic polyamides to form covalent chemical bonds. The reactive groups are generally bonded to the UV absorber radical directly or via a bridge member. Suitable reactive groups are for example those which contain at least one detachable substituent attached to an aliphatic, aromatic or heterocyclic radical or in which the radicals mentioned contain a radical suitable for reaction with the fibre material, for example a triazine radical.

Suitable further reactive groups include those which contain at least one activated unsaturated group, in particular an unsaturated aliphatic group, for example a vinyl, halovinyl, styryl, acryloyl or methacryloyl group, or at least one polymerizable ring system. Examples of such groups are unsaturated groups containing halogen atoms, such as halomaleic acid radicals and halopropiolic acid radicals, α- or β-bromo- or chloro-acryloyl, halogenated vinylacetyl groups, halocrotonyl or halomethacryloyl groups. Also suitable are those groups which are readily converted, for example by elimination of hydrogen halide, into halogen-containing unsaturated groups, for example dichloropropionyl or dibromopropionyl. Halogen atoms are here to be understood as meaning fluorine, chlorine, bromine and iodine atoms but also pseudohalogen atoms, for example cyano. Examples of further detachable atoms or groups are ammonium including hydrazinium, sulfato, thiosulfato, phosphato, acetoxy, propionoxy or carboxypyridinium.

Suitable reactive UV absorbers for the process of the present invention are preferably compounds of the formula ##STR21## where B₃ and B₄ are each independently of the other an aliphatic bridge member; U is the radical of a UV absorber from the group of the 2-hydroxybenzophenones, benzotriazoles, 2-hydroxyphenyl-1,3,5-triazines, oxalodiamides, acrylates, substituted or unsubstituted benzoic acids and esters and radicals of the formula ##STR22## where (R₄₀)₀₋₃ represents 0 to 3 identical or different radicals R₄₀ selected from the group consisting of sulfo, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, hydroxyl, carboxyl, nitro and C₁ -C₄ alkylcarbonylamino,

R₄₁ is hydrogen, sulfo, C₁ -C₄ alkyl or C₁ -C₄ alkoxy,

M₂ is a group --NR₃₀ --CO-- or --NR₃₀ --SO₂ --,

R₃₀ is hydrogen or C₁ -C₄ alkyl,

W₂ is a group --NR₄₂ --, --O-- or --S--,

R₄₂ is hydrogen or substituted or unsubstituted C₁ -C₄ alkyl,

W₁ is a radical --C(O)O--, --O(O)C--, --C(O)NH-- or --HN(O)C--,

X₇ is halogen, hydroxyl, sulfo, C₁ -C₄ alkylsulfonyl, phenylsulfonyl, substituted or unsubstituted amino, 3-carboxypyridin-1-yl or 3-carbamoylpyridin-1-yl,

T₅ independently has one of the meanings indicated for X₇ or is an optionally further substituted alkoxy, aryloxy, alkylthio or arylthio radical or is a nitrogen-containing heterocyclic radical or is a reactive radical of the formula ##STR23## where B₅ is an aliphatic, cycloaliphatic, aromatic or aromatic-aliphatic bridge member or together with --NR₄₆ -- or --NR₄₇ -- is a heterocyclic ring,

R₄₆ and R₄₇ are each independently of the other hydrogen or substituted or unsubstituted C₁ -C₄ alkyl,

X₈ is halogen, hydroxyl, substituted or unsubstituted amino, 3-carboxypyridin-1-yl or 3-carbamoylpyridin-1-yl,

T₆ independently has one of the meanings indicated for X₈ or is an optionally further substituted alkoxy, aryloxy, alkylthio or arylthio radical or is a nitrogen-containing heterocyclic radical or independently a radical U--(B₄)_(c) --(W₁)_(d) --(B₃)_(e) --W₂ --, where U, B₄, B₃, W₁ and W₂ are each as defined above,

R₄₄ is hydrogen, unsubstituted or hydroxyl-, sulfo-, sulfato-, carboxyl- or cyano-substituted C₁ -C₄ alkyl or a radical ##STR24## R₄₅ is hydrogen or C₁ -C₄ alkyl, R₄₃ is hydrogen, hydroxyl, sulfo, sulfato, carboxyl, cyano, halogen, C₁ -C₄ alkoxycarbonyl,

C₁ -C₄ alkanoyloxy, carbamoyl or the group --SO₂ --Y₂,

alk and alk" are independently of each other C₁ -C₇ alkylene,

arylen is an unsubstituted or sulfo-, carboxyl-, C₁ -C₄ alkyl-, C₁ -C₄ alkoxy- or halogen-substituted phenylene or naphthylene radical,

Y₂ is vinyl or a radical --CH₂ -CH₂ --Z₂ and Z₂ is a leaving group,

W₃ is --O-- or --NR₄₅ --,

W₄ is a group --SO₂ --NR₄₄ --, --CONR₄₄ -- or --NR₄₄ CO--, and

c, d, e and f are each independently of the others 0 or 1, with d being 0 when e is 0, with the proviso that the compounds of the formula (26) have at least one sulfo or sulfato group and at least one alkali-detachable group.

An aliphatic bridge member B₃ or B₄ is for example a straight-chain or branched C₁ -C₁₂ alkylene, preferably a straight-chain or branched C₁ -C₆ alkylene. Examples of particularly preferred alkylene radicals B₃ and B₄ are methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 2-methyl-1,5-pentylene and 1,6-hexylene, in particular methylene and 1,2-ethylene.

An aliphatic bridge member B₅ can be for example straight-chain or branched and optionally hydroxyl-, sulfo- or sulfato-substituted and/or --O-interrupted C₂ -C₁₂ alkylene. Preferably B₅ is straight-chain or branched C₂ -C₆ alkylene which may be substituted by hydroxyl, sulfo or sulfato. Examples of particularly preferred alkylene radicals B₅ are 1,2-ethylene, 1,2-propylene, 1,3-propylene, 2-hydroxy-1,3-propylene, 1,4-butylene, 2-methyl-1,5-pentylene and 1,6-hexylene.

A cycloaliphatic bridge member B₅ is for example cyclohexylene or the radical of the formula ##STR25## or --NR₄₆ -- and --NR₄₇ -- are combined with B₅ into a ring, for example a piperazine ring.

Examples of aromatic bridge members B₅ are unsubstituted or, for example, sulfo-, carboxyl-, C₁ -C₄ alkyl-, C₁ -C₄ alkoxy- or halogen-substituted 1,2-, 1,3- or 1,4-phenylene, unsubstituted or sulfo-substituted naphthylene or a radical of the formula ##STR26## where Z₃ is for example --CO--, --NHCO--, --NHCONH--, --(CH)₁₋₄ --, --NH--, --CH═CH--, --O--, --SO₂ -- or --N═N--; and (R₄₈)₀₋₂ and (R₄₉)₀₋₂ independently of each other represent 0 to 2 identical or different radicals selected from the group consisting of sulfo, methyl, methoxy and chlorine.

Preferable for use as aromatic bridge member B₅ are unsubstituted or sulfo-, carboxyl-, chlorine-, methyl- or methoxy-substituted 1,3- or 1,4-phenylene, naphthylene substituted by 1 or 2 sulfo groups, or a radical of the formula ##STR27## where Z₄ is --NHCONH--, --O--, --NH--, --CH═CH-- or --CH₂ --; and R₅₀ is hydrogen or sulfo.

Examples of particularly preferred aromatic bridge members B₅ are 1,3-phenylene, 1,4-phenylene, 4-methylphenylene-1,3,4-sulfophenylene-1,3,3-sulfophenylene-1,4, 3,6-disulfophenylene-1,4,4,6-disulfophenylene-1,3,3,7-disulfonaphthylene-1,5, 4,8-disulfonaphthylene-2,6,2,2'-disulfodiphenylene-4,4', 4,4'phenyleneurea-2,2'-disulfonic acid or 2,2'-disulfostilbenylene-4,4' and in particular 4-sulfophenylene-1,3,3-sulfophenylene-1,4,3,6-disulfophenylene-1,4 or 4,6-disulfophenylene-1,3.

An example of aromatic-aliphatic bridge members B₅ is phenylene-C₁ -C₄ alkylene, unsubstituted or substituted in the phenylene moiety, for example by sulfo, methyl, methoxy, carboxyl or chlorine. An aromatic-aliphatic bridge member B is preferably unsubstituted phenylenemethylene or phenylenemethylene substituted by sulfo, methyl or methoxy in the phenylene moiety.

B₅ is preferably C₂ -C₆ alkylene, which may be substituted by hydroxyl, sulfo or sulfato, unsubstituted or sulfo-, carboxyl-, chlorine-, methyl- or methoxy-substituted 1,3- or 1,4-phenylene, naphthylene substituted by 1 or 2 sulfo groups, or a radical of the formula ##STR28## where Z₄ is --NHCONH--, --O--, --NH--, --CH═CH-- or --CH₂ --; and R₅₀ is hydrogen or sulfo.

Particularly preferably B₅ is 4-sulfophenylene-1,3,3-sulfophenylene-1,4, 3,6-disulfophenylene-1,4 or 4,6-disulfophenylene-1,3.

R₄₆ and R₄₇ are each independently of the other for example hydrogen or unsubstituted or, for example, halogen-, hydroxyl-, cyano-, C₁ -C₄ alkoxy-, C₁ -C₄ alkoxycarbonyl-, carboxyl-, sulfamoyl-, sulfo- or sulfato-substituted C₁ -C₄ alkyl. Preferably R₄₆ and R₄₇ are each independently of the other hydrogen or C₁ -C₄ alkyl, particularly preferably hydrogen, methyl or ethyl.

c and d are each preferably 0.

R₄₂ is for example hydrogen or unsubstituted or, for example, halogen-, hydroxyl-, cyano-, C₁ -C₄ alkoxy-, C₁ -C₄ alkoxycarbonyl-, carboxyl-, sulfamoyl-, sulfo- or sulfato-substituted C₁ -C₄ alkyl. Preferably R₄₂ is hydrogen or C₁ -C₄ alkyl, particularly preferably hydrogen, methyl or ethyl.

A 2-hydroxyphenyl-1,3,5-triazine radical U has for example the formula ##STR29## where z is an integer from 1 to 3 and Q₄, Q₅ and Q₆ are each independently of the others hydrogen, hydroxyl, C₁ -C₁₂ alkyl, C₁ -C,₈ alkoxy or unsubstituted or hydroxyl-substituted C₁ -C₄ alkoxy-C₁ -C₄ alkoxy.

Examples of suitable 2-hydroxyphenyl-1,3,5-triazine radicals U are the radical of 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2- 2-hydroxy-4-(2-hydroxy-3-butyloxypropyloxy)phenyl!-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-methoxy-6-sulfophenyl)-4,6-bis(phenyl)-1,3,5-triazine or 2- 2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl!-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

The benzotriazole radical U has for example the formula ##STR30## where R₅₁ and R₅₂ are independently of each other hydrogen; C₁ -C₄ alkyl; C₁ -C₄ alkoxy; halogen; hydroxyl; nitro; sulfo or carboxyl.

A 2-hydroxybenzophenone radical U has for example the formula ##STR31## where (A₃)₀₋₃ represents 0 to 3 identical or different radicals selected from the group consisting of halogen, hydroxyl, sulfo, C₁ -C₁₂ alkoxy or phenyl-C₁ -C₄ alkoxy and (A₄)₀₋₂ represents 0 to 2 identical or different radicals selected from the group consisting of halogen, hydroxyl, sulfo, C₁ -C₁₂ alkoxy or phenyl-C₁ -C₄ alkoxy.

Examples of suitable 2-hydroxybenzophenone radicals U are the radical of 2,4-dihydroxy-, 2-hydroxy-4-methoxy-, 2-hydroxy-4-octoxy-, 2-hydroxy-4-decyloxy-, 2-hydroxy-4-dodecyloxy-, 2-hydroxy-4-methoxy-5-sulfo-, 2-hydroxy-4-benzyloxy-, 4,2',4'-trihydroxy- or 2'-hydroxy-4,4'-dimethoxy-benzophenone.

An oxalanilide radical U has for the example the formula ##STR32## where x and y are each independently of the other an integer from 0 to 3 subject to the proviso that the sum of (x+y)≧1, and each substituent L₂ is independently of the others sulfo; alkyl, alkoxy or alkylthio each with 1 to 22 carbon atoms and unsubstituted or substituted in the alkyl moiety by sulfo; or phenoxy or phenylthio unsubstituted or substituted on the phenyl ring by sulfo.

Examples of suitable oxalanilide radicals U are the radical of 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy-5,5'-di-tert-butyl-oxanilide, 2,2'-di-dodecyloxy-5,5'di-tert-butyl-oxanilide, 2-ethoxy-2'-ethyloxanilide, 2-methoxy-5-sulfooxanilide, 2-ethoxy-5-sulfooxanilide, 2,5-dimethoxyoxanilide, 2-ethoxy-5-tert-butyl-2'-ethyloxanilide alone or mixed with the radical of 2-ethoxy-2'-ethyl-5,4'-di-tert-butyl-oxanilide, or mixtures of the radicals of o- and p-methoxy- and also of o- and p-ethoxy-disubstituted oxanilides.

Suitable acrylate radicals U are C₁ -C₁₀ alkyl acrylates which are unsubstituted or substituted by cyano or carbo-C₁ -C₄ alkoxy in the α-position, carry a phenyl, C₁ -C₄ alkoxyphenyl or indolinyl radical in one β-position and are unsubstituted or substituted by phenyl, C₁ -C₄ alkoxyphenyl or C₁ -C₄ alkyl in the other β-position.

Examples of acrylate radicals U are the radical of ethyl or isooctyl α-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methyl or butyl α-cyano-β-methyl-p-methoxycinnamate, methyl α-carbomethoxy-p-methoxycinnamate or N-(β-carbomethoxy-p-cyanovinyl)-2-methylindoline.

A substituted or unsubstituted benzoic acid or ester radical U is for example an unsubstituted or hydroxyl- or C₁ -C₄ alkyl-substituted benzoic acid radical or its phenyl, C₁ -C₈ alkylphenyl or C₁ -C₁₈ alkyl ester. Examples are the radical of benzoic acid, 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis(4-tert-butylbenzoyl)resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate or 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

When U is a radical of the above-indicated formula (27), (R₄₀)₀₋₃ preferably denotes 0 to 3 identical or different radicals R₄₀ selected from the group consisting of sulfo, methyl, methoxy, hydroxyl and carboxyl, R₄₁ is preferably hydrogen, and M₂ is preferably a group --NH--CO-- or --NH--SO₂ --. U is in this case preferably a radical of the formula ##STR33## where (R₅₃)0-1 denotes 0 or 1 radical R₅₃ selected from the group consisting of sulfo, methyl, methoxy, hydroxyl and carboxyl and M₃ is a group --NH--CO-- or --NH--SO₂ --.

Particularly preferably U is the radical of an oxalic diarylamide of the formula ##STR34## where R₃₇ is unsubstituted or hydroxyl- or alkoxy-substituted C₁ -C₅ alkyl or unsubstituted or C₁ -C₅ alkyl-substituted benzyl;

R₃₉ is hydrogen; halogen; C₁ -C₁₂ alkyl; phenyl-C₁ -C₅ alkyl or C₁ -C₅ alkoxy;

B₂ is a direct bond or a bivalent radical of the formula-O--L₃ --, where

L₃ is unsubstituted or hydroxyl-substituted C₁ -C₆ alkylene;

M" is hydrogen or an alkali metal and

v is 2; 1or 0.

A C₁ -C₅ alkyl R₃₇ is for example methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl or isoamyl;

A halogen R₃₉ is for example fluorine, bromine or chlorine. Chlorine is preferred. A C₁ -C₁₂ alkyl R₃₉ can be branched or unbranched radicals, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl, isoamyl, pentyl, neopentyl, tert-pentyl, hexyl, isohexyl, heptyl, octyl, isooctyl, nonyl, decyl, undecyl or dodecyl. A phenyl-C₁ -C₅ alkyl R₃₉ is for example phenethyl, phenylpropyl, phenylbutyl or preferably benzyl.

A C₁ -C₅ alkoxy R₃₉ is for example methoxy, ethoxy, isopropoxy, isobutoxy, tert-butoxy or tert-amyloxy.

A C₁ -C₆ alkylene L₃ is a bivalent saturated hydrocarbon radical, for example methylene, ethylene, propylene, trimethylene, tetramethylene, ethylethylene, pentamethylene or hexamethylene.

An alkali metal M" is for example lithium, sodium or potassium. Sodium is preferred.

Particularly suitable for use as a radical of the oxalic diarylamide of the formula (35) is a compound in which L₃ is trimethylene or ##STR35##

A further preferred oxalic diarylamide radical conforms to the above-indicated formula (35) where R₃₉ is hydrogen, C₁ -C₁₂ alkyl or C₁ -C₅ alkoxy. Likewise preferred is an oxalic diarylamide radical of the above-indicated formula (35) where

R₃₇ is C₁ -C₃ alkyl;

R₃₉ is hydrogen, C₁ -C₃ alkyl or C₁ -C₃ alkoxy;

B₂ is a direct bond or the radical -- O--(CH₂)₃ !_(m) ; and

m is 0 or 1.

Very particular preference for use as oxalic diarylamide radical is given to a compound of the formula (35) where

v is 0 or 1;

R₃₇ is methyl or ethyl;

R₃₉ is hydrogen or C₁ -C₃ alkoxy; and

B₂ is a direct bond.

The reactive UV absorbers of the formula (26) are known or can be prepared for example by reacting a compound of the formula

    U--(B.sub.4).sub.c --(W.sub.1).sub.d --(B.sub.3).sub.e --W.sub.2 --H(36),

a compound of the formula ##STR36## and a compound of the formula

    T.sub.5 *--H                                               (38)

where U, B₃, B₄, W₁, W₂, X₇, c, d and e are each as defined above, Hal is halogen, preferably fluorine or chlorine, and T₅ * has the meanings indicated above for T₅ other than halogen, with one another, the order of the elementary reactions being freely choosable having regard to the starting compounds to be reacted with one another.

The application of the reactive UV absorbers can take place before, during or after the application of the direct dyes (dyeing), by an exhaust or continuous process. The application during dyeing is preferred. Particular preference is given to applying the UV absorbers together with the direct dyes.

Preference for the process of the present invention is given to combinations of dyes containing the radicals of the formulae (4a), (4b), (5a), (5b), (6), (7), (8), (9a) or (9b) with UV absorbers of the formulae (10), (11), (12) or (13).

Particular preference for the process of the present invention is given to combinations of dyes containing the radicals of the formulae (4a), (4b), (5a), (5b), (6), (7), (8), (9a) or (9b) with reactive UV absorbers of the formula (26).

Very particular preference for the process of the present invention is given to combinations of dyes containing the radicals of the formulae (4a), (4b), (5a), (5b), (6), (7), (8), (9a) or (9b) with reactive UV absorbers of the formula (26) where U is the radical of the formula (35).

Cellulosic fibre materials are to be understood as meaning for example the natural cellulose fibre, such as cotton, linen and hemp, and also cellulose pulp and regenerated cellulose. The direct dyes are also suitable for treating hydroxyl-containing fibres present in blend fabrics, for example blends of cotton with polyester fibres or polyamide fibres. Cellulosic fibre materials having a density between 30 and 200 g/m² are preferred for the use according to the present invention. Cotton is the preferred cellulosic fibre material. The fibres mentioned can be present in various forms, for example as staple or yarns or as wovens or knits.

The direct dyes can be applied to the fibre material and fixed on the fibre in various ways, in particular in the form of aqueous dye solutions and print pastes. They are suitable not only for the exhaust process but also for dyeing by the pad-dyeing process, whereby the material is impregnated with aqueous dye solutions with or without a salt content and the dyes are fixed after an alkali treatment or in the presence of alkali with or without heating. After fixing, the dyeings or prints are thoroughly rinsed with cold and hot water in the presence or absence of an agent which has a dispersing effect and promotes the diffusion of the unfixed portions. The customary dyeing and printing processes are employed.

The dyeing liquors may contain the generally customary additives, for example the aqueous solutions of inorganic salts, for example of alkali metal chlorides or alkali metal sulfates, alkali metal hydroxides, ureas, thickenings, for example alginate thickenings, water-soluble cellulose alkyl ethers and also dispersing, levelling and deaerating auxiliaries, antifoams, penetration accelerants and migration inhibitors, also sodium m-nitrobenzenesulfonate and, as further thickeners, for example methylcellulose, starch ethers, emulsion thickenings, preferably an alginate, for example sodium alginate, and also wetting agents.

Preference for the use according to the present invention is given to dyeing by the exhaust method. Exhaust dyeing generally takes place in an aqueous medium, at a liquor ratio of, for example, 2:1 to 60:1, in particular a liquor ratio of 5:1 to 20:1, a dyebath pH of, for example, 6 to 13 and a temperature of, for example, 40 to 120° C., in particular a temperature of 60 to 95° C.

The cellulose fibre materials treated with the direct dyes and UV absorbers are notable for a very high sun protection factor. The sun protection factor is defined as the ratio of the harmful dose of UV energy on protected skin to the harmful dose of UV energy on unprotected skin. Accordingly, a sun protection factor is also a measure of the UV transmissivity of untreated fibre materials and of fibre materials treated with the direct dyes and UV absorbers used in this invention. The UV transmissivity of fibre materials can be measured for example in a transmission measurement using a double monochromator spectrophotometer equipped with an Ulbricht sphere.

The sun protection factor can be calculated for example by the method described by B. L. Diffey and J. Robson in J. Soc. Cosmet. Chem. 40, 127-133 (May/June 1989).

The examples which follow illustrate the invention. The temperatures are indicated in degrees Celsius. Parts and percentages are by weight, unless otherwise stated. Parts by weight relate to parts by volume as the kilogram to the liter.

EXAMPLE 1

Twelve specimens, each weighing 10 g, of a bleached cotton tricot having a weight of 185 g/m² and a thickness of 0.85 mm are treated individually in an AHIBA® dyeing machine at a liquor ratio of 25:1 in twelve different liquors.

Liquor 1 contains 0.013 g of a direct dye which, in the form of the free acid, conforms to the following formula: ##STR37## 0.5 g/l of a commercial dyeing auxiliary, for example a penetration accelerant, and 0.5 g/l of calcined sodium carbonate.

Liquor 2 corresponds to liquor 1, but additionally contains 0.075 g of a UV absorber of the formula ##STR38##

Liquor 3 contains 0.011 g of a direct dye which, in the form of the free acid, conforms to the following formula: ##STR39## 0.5 g/l of a commercial dyeing assistant, for example a penetration accelerant, and 0.5 g/l of calcined sodium carbonate.

Liquor 4 corresponds to liquor 3, but additionally contains 0.075 g of a UV absorber of the formula (200).

Liquor 5 contains 0.01 g of a direct dye which, in the form of the free acid, conforms to the following formula: ##STR40## 0.5 g/l of a commercial dyeing assistant, for example a penetration accelerant, and 0.5 g/l of calcined sodium carbonate.

Liquor 6 corresponds to liquor 5, but additionally contains 0.075 g of a UV absorber of the formula (200).

Liquor 7 contains 0.008 g of a direct dye which, in the form of the free acid, conforms to the following formula: ##STR41## 0.5 g/l of a commercial dyeing assistant, for example a penetration accelerant, and 0.5 g/l of calcined sodium carbonate.

Liquor 8 corresponds to liquor 7, but additionally contains 0.075 g of a UV absorber of the formula (200).

Liquor 9 contains 0.009 g of a direct dye which, in the form of the free acid, conforms to the following formula: ##STR42## 0.5 g/l of a commercial dyeing assistant, for example a penetration accelerant, and 0.5 g/l of calcined sodium carbonate.

Liquor 10 corresponds to liquor 9, but additionally contains 0.075 g of a UV absorber of the formula (200).

Liquor 11 contains 0.008 g of a direct dye which, in the form of the free acid, conforms to the following formula: ##STR43## 0.5 g/l of a commercial dyeing assistant, for example a penetration accelerant, and 0.5 g/l of calcined sodium carbonate.

Liquor 12 corresponds to liquor 11, but additionally contains 0.075 g of a UV absorber of the formula (200).

The cotton tricot specimens are introduced into the dyeing liquors at 40° C.; after 5 minutes the dyebath is heated up at a rate of 2° C./minute to a temperature of 95° C. and left at that temperature for 60 minutes. At 10 minutes and 20 minutes from the attainment of 95° C. 5 g/l of sodium chloride is added each time.

Following a total dyeing time of 45 minutes, the liquors are cooled down to 60° C., the dyed specimens are removed from the liquors, rinsed with cold water, centrifuged and then dried at 100° C.

Thereafter the transmission spectra of the specimens are measured in the UV region and the sun protection factors determined. The sun protection factors found are reproduced in Table 1.

                  TABLE 1     ______________________________________     Specimen treated with                     Sun protection factor according to     liquor No.      CIE D 65 CIE S. Europe     ______________________________________     untreated       7        8     1               41       41     2               182      198     3               32       40     4               138      164     5               44       50     6               176      207     7               28       31     8               141      180     9               13       14     10              203      270     11              40       42     12              138      154     ______________________________________

EXAMPLE 2

Example 1 is repeated, except that in liquors 2, 4, 6, 8, 10 and 12 the 0.075 g of the UV absorber of the formula (200) is replaced by the same amount of a UV absorber of the formula ##STR44##

The sun protection factors found for the twelve specimens are reproduced in Table 2:

                  TABLE 2     ______________________________________     Specimen treated with                     Sun protection factor according to     liquor No.      CIE D 65 CIE S. Europe     ______________________________________     untreated       7        8     1 a             41       41     2 a             145      198     3 a             32       40     4 a             114      177     5 a             44       50     6 a             134      211     7 a             28       31     8 a             89       136     9 a             13       14     10 a            74       125     11 a            40       42     12 a            152      206     ______________________________________

EXAMPLE 3

Examples 1 and 2 are repeated with the 0.85 mm 185 g/m² bleached cotton tricot replaced by a cotton cretonne having a weight of 135 g/m² and a thickness of 0.2 mm.

The sun protection factors found for the eighteen specimens are reproduced in Table 3:

                  TABLE 3     ______________________________________     Specimen treated with                     Sun protection factor according to     liquor No.      CIE D 65 CIE S. Europe     ______________________________________     untreated       4        4     1'              12       12     2'              29       31      2a'            34       38     3'              12       14     4'              26       28      4a'            24       31     5'              15       16     6'              25       27      6a'            24       29     7'              8        9     8'              24       27      8a'            24       31     9'              6        7     10'             29       32     10a'            25       32     11'             13       14     12'             27       29     12a'            35       40     ______________________________________ 

What is claimed is:
 1. A process which increases the Sun Protection Factor of an undyed cellulosic fibre material by at least a factor of 5, which comprises treating the cellulosic fibre material with 0.001 to 0.2% by weight, based on the weight of the fibre material of at least one direct dye, and with 0.2 to 2% by weight, based on the weight of the fibre material of at least one UV absorber, or treating the cellulosic fibre material with 0.2 to 2% by weight, based on the weight of the fibre material of at least one direct dye and 0.05 to 0.2% by weight, based on the weight of the fibre material of at least one UV absorber.
 2. A process according to claim 1, wherein the cellulosic fibre material used is cotton.
 3. A process as claimed in claim 1, wherein the cellulosic fibre material used has a density between 30 and 200 g/m².
 4. A process according to claim 1, wherein the UV absorber used is a 2-hydroxybenzophenone of the formula ##STR45## where R₉ is hydrogen, hydroxyl, C₁ -C₁₄ alkoxy or phenoxy, R₁₀ is hydrogen, halogen, C₁ -C₄ alkyl or sulfo, R₁₁ is hydrogen, hydroxyl or C₁ -C₄ alkoxy, and R₁₂ is hydrogen, hydroxyl or carboxyl.
 5. A process according to claim 1, wherein the UV absorber used is a 2-(2'-hydroxyphenyl)benzotriazole of the formula ##STR46## where R₁₃ is hydrogen, chlorine, sulfo, C₁ -C₁₂ alkyl, C₅ -C₆ cycloalkyl, (C₁ -C₈ alkyl)phenyl, C₇ -C₉ phenylalkyl or sulfonated C₇ -C₉ phenylalkyl, R₁₄ is hydrogen, chlorine, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxyl or sulfo, R₁₅ is C₁ -C₁₂ alkyl, chlorine, sulfo, C₁ -C₄ alkoxy, phenyl, (C₁ -C₈ alkyl)phenyl, C₅ -C₆ cycloalkyl, C₂ -C₉ alkoxycarbonyl, carboxyethyl, C₇ -C₉ phenylalkyl or sulfonated C₇ -C₉ phenylalkyl, R₁₆ is hydrogen, chlorine, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₂ -C₉ alkoxycarbonyl, carboxyl or sulfo, and R₁₇ is hydrogen or chlorine.
 6. A process according to claim 1, wherein the UV absorber is used together with the direct dye.
 7. A process according to claim 1, wherein the UV absorber used is a reactive UV absorber.
 8. A process according to claim 1, wherein the direct dye used has the formula

    A.sub.1 --B.sub.1 --A.sub.2                                ( 1)

where B₁ is a bridge member and A₁ and A₂ are independently of each other the radical of a monoazo, polyazo, metal complex azo, stilbene or anthraquinone dye, or where B₁ and A₁ are each as defined above and A₂ is a phenyl or naphthyl radical substituted by a heterocyclic radical or by a benzoylamino or phenylamino radical, or where B₁ is a direct bond and A₁ and A₂ are each the radical of a metal complex azo dye.
 9. A process according to claim 8, wherein A₁ and A₂ are radicals of the formulae ##STR47## where D₁ is the radical of a diazo component of the benzene or naphthalene series, M₁ is the radical of a middle component of the benzene or naphthalene series, and K₁ is the radical of a coupling component of the benzene or naphthalene series.
 10. A process according to claim 8, wherein A₁ and A₂ are radicals of the formulae ##STR48## where the oxygen or the carboxyl group is bonded to the radical Q₁, Q₂ or Q₃ in an ortho position relative to the azo group and Q₁, Q₂ or Q₃ are each independently of the others a radical of the benzene or naphthalene series.
 11. A process according to claim 8, wherein A₁ and A₂ are radicals of the formula ##STR49## .
 12. A process according to claim 8, wherein A₁ and A₂ are radicals of the formula ##STR50## where G₁ is C₂ -C₆ alkylene, cyclohexylene, phenylenemethylene or phenylene.
 13. A process according to claim 1, wherein the direct dye used is a phthalocyanide direct dye containing the radical of the formula ##STR51## where Pc is the radical of a copper or nickel phthalocyanine, W is --OH and/or --NR₇ R₈, R₇ and R₈ are independently of each other hydrogen or unsubstituted or hydroxyl- or sulfo-substituted C₁ -C₄ alkyl, R₆ is hydrogen or C₁ -C₄ alkyl, E is unsubstituted or C₁ -C₄ alkyl-, halogen-, carboxyl- or sulfo-substituted phenylene, or a C₂ -C₆ alkylene, and k is 1,2 or
 3. 14. A process according to claim 1, wherein the direct dye used is a dioxazine direct dye containing the radicals of the formulae ##STR52## where E₁ is unsubstituted or C₁ -C₄ alkyl-, halogen-, carboxyl- or sulfo-substituted phenylene or a C₂ -C₆ alkylene.
 15. A process according to claim 7, wherein the reactive UV absorber used is the compound of the formula ##STR53## where B₃ and B₄ are each independently of the other an aliphatic bridge member, U is the radical of a UV absorber from the group of the 2-hydroxybenzophenones, benzotriazoles, 2-hydroxyphenyl-1,3,5-triazines, oxalodiamides, acrylates, substituted or unsubstituted benzoic acids and esters and radicals of the formula ##STR54## where (R₄₀)₀₋₃ represents 0 to 3 identical or different radicals R₄₀ selected from the group consisting of sulfo, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen, hydroxyl, carboxyl, nitro and C₁ -C₄ alkylcarbonylamino,R₄₁ is hydrogen, sulfo, C₁ -C₄ alkyl or C₁ -C₄ alkoxy, M₂ is a group --NR₃₀ --CO-- or --NR₃₀ --SO₂ --, R₃₀ is hydrogen or C₁ -C₄ alkyl, W₂ is a group --NR₄₂ --, --O-- or --S--, R₄₂ is hydrogen or substituted or unsubstituted C₁ -C₄ alkyl, W₁ is a radical --C(O)O--, --O(O)C--, --C(O)NH-- or --HN(O)C--, X₇ is halogen, hydroxyl, sulfo, C₁ -C₄ alkylsulfonyl, phenylsulfonyl, substituted or unsubstituted amino, 3-carboxypyridin-1-yl or 3-carbamoylpyridin-1-yl, T₅ independently has one of the meanings indicated for X₇ or is an optionally further substituted alkoxy, aryloxy, alkylthio or arylthio radical or is a nitrogen-containing heterocyclic radical or is a reactive radical of the formula ##STR55## where B₅ is an aliphatic, cycloaliphatic, aromatic or aromatic-aliphatic bridge member or together with --NR₄₆ -- or --NR₄₇ -- is a heterocyclic ring, R₄₆ and R₄₇ are each independently of the other hydrogen or substituted or unsubstituted C₁ -C₄ alkyl, X₈ is halogen, hydroxyl, substituted or unsubstituted amino, 3-carboxypyridin-1-yl or 3-carbamoylpyridin-1-yl, T₆ independently has one of the meanings indicated for X₈ or is an optionally further substituted alkoxy, aryloxy, alkylthio or arylthio radical or is a nitrogen-containing heterocyclic radical or independently a radical U-(B₄)_(c) --(W₁)_(d) --(B₃)_(e) --W₂ --, where U, B₄, B₃, W₁ and W₂ are each as defined above, R₄₄ is hydrogen, unsubstituted or hydroxyl-, sulfo-, sulfato-, carboxyl- or cyano-substituted C₁ -C₄ alkyl or a radical ##STR56## R₄₅ is hydrogen or C₁ -C₄ alkyl, R₄₃ is hydrogen, hydroxyl, sulfo, sulfato, carboxyl, cyano, halogen, C₁ -C₄ alkoxycarbonyl, C₁ -C₄ alkanoyloxy, carbamoyl or the group --SO₂ --Y₂, alk and alk" are independently of each other C₁ -C₇ alkylene, arylen is an unsubstituted or sulfo-, carboxyl-, C₁ -C₄ alkyl-, C₁ -C₄ alkoxy- or halogen-substituted phenylene or naphthylene radical, Y₂ is vinyl or a radical --CH₂ -CH₂ --Z₂ and Z₂ is a leaving group, W₃ is --O-- or --NR₄₅ --, W₄ is a group --SO₂ --NR₄₄ --, --CONR₄₄ -- or --NR₄₄ CO--, and c, d, e and f are each independently of the others 0 or 1, with d being 0 when e is 0, with the proviso that the compounds of the formula (26) have at least one sulfo or sulfato group and at least one alkali-detachable group.
 16. A process according to claim 15, wherein the reactive UV absorber used is the compound of the formula (26) where U is a radical of an oxalic diarylamide of the formula ##STR57## where R₃₇ is unsubstituted or hydroxyl- or alkoxy-substituted C₁ -C₅ alkyl or unsubstituted or C₁ -C₅ alkyl-substituted benzyl;R₃₉ is hydrogen, halogen, C₁ -C₁₂ alkyl, phenyl-C₁ -C₅ alkyl or C₁ -C₅ alkoxy, B₂ is a direct bond or a bivalent radical of the formula --O----L₃ --, where L₃ is unsubstituted or hydroxyl-substituted C₁ -C₆ alkylene, M" is hydrogen or an alkali metal and v is 2, 1 or
 0. 17. A process according to claim 1, wherein the UV absorber used is a 2-(2'-hydroxyphenyl)-s-triazine of the formula ##STR58## where R₁₈ is hydrogen, halogen, C₁ -C₄ alkyl or sulfo,R₁₉ is hydrogen, C₁ -C₄ alkyl, C₁ -C₄ alkoxy or hydroxyl, R₂₀ is hydrogen or sulfo, and R₂₁ and R₂₂ are independently of each other C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₅ -C₆ cycloalkyl, phenyl or C₁ -C₄ alkyl- and/or hydroxyl-substituted phenyl.
 18. A process according to claim 1, wherein the UV absorber used is an s-triazine compound of the formula ##STR59## where at least one of the substituents R₂₃, R₂₄ and R₂₅ is a radical of the formula ##STR60## where A is C₃ -C₄ alkylene or 2-hydroxytrimethylene and M' is sodium, potassium, calcium, magnesium, ammonium or tetra-C₁ -C₄ alkylammonium and b is 1 or 2, and the remaining substituent is or the remaining substituents are independently of each other C₁ -C₁₂ alkyl, phenyl, C₁ -C₁₂ alkyl or phenyl attached to the triazinyl radical by oxygen, sulfur, imino or C₁ -C₁₁ alkylimino, or a radical of the formula (14). 